The present disclosure relates to a case for an endless transmission member. The case is attached to a vehicle-mounted internal combustion engine.
Japanese Laid-Open Patent Publication No. 07-063025 discloses a chain case for accommodating chains that are looped over sprockets of a vehicle-mounted internal combustion engine. The chain case of this publication includes a first case member attached to the vehicle-mounted internal combustion engine and a second case member attached to the first case member. The first case member and the second case member define a chain chamber for accommodating chains. The chain case of this publication includes a communication hole for returning lubricant that has scattered inside the chain chamber to the inside of the internal combustion engine.
In a case in which the communication hole is provided in the chain case like the chain case disclosed in the above-described publication, the greater the opening area of the communication hole, the more easily the lubricant returns to the inside of the internal combustion engine. However, the area provided for the opening area of the communication hole is limited. Thus, there is a demand for a structure that efficiently returns the lubricant to the inside of the internal combustion engine without increasing the opening area of the communication hole provided in the chain case.